LED-lamp-free electro-luminescence atmosphere coating device for interior and exterior decoration of automobile

Abstract

The invention discloses an automobile interior and exterior decoration LED-lamp-free electro-luminescent atmosphere coating device which comprises an electro-luminescent coating material, a power supply system and a control module. The electro-luminescence coating material is coated on the surfaces of interior and exterior decorations of an automobile, the power supply system provides electric energy for the material, and the control module controls output of the power supply system to adjust the luminescence effect. A novel automobile atmosphere lighting mode is provided, a traditional LED lamp is not needed, and the advantages of being energy-saving, environmentally friendly, convenient to install, high in customizable degree and the like are achieved.

Description

[0001] This invention relates to an LED-free electro-cooled light atmosphere coating device for automotive interior and exterior trim.

[0002] Light-emitting devices equipped with a light-emitting layer include, for example, electroluminescent devices using organic electroluminescent elements with an organic semiconductor as the light-emitting layer. The light-emitting layer is generally an organic functional layer containing the light-emitting layer disposed between a pair of opposing electrodes.

[0003] When the electroluminescent device is used for color display, it is provided with multiple light-emitting layers corresponding to the emission wavelength regions of each of the colors red (R), green (G), and blue (B). The light-emitting layers corresponding to each of the above colors are disposed on the substrate in a predetermined arrangement.

[0004] In electroluminescent devices, in order to improve light-emitting characteristics such as brightness and luminous efficiency, an electron injection layer is often formed to promote the injection of electrons from the electrodes into the light-emitting layer. This electron injection layer is generally formed by vapor deposition (see, for example, Patent Documents 1 and 2).

[0005] Patent Document 1: Japanese Patent Application Publication No. 2001-160487

[0006] Patent Document 2: Japanese Patent Application Publication No. 2000-182782

[0007] However, if all electron injection layers are set in the same state for multiple light-emitting layers, the luminescence characteristics will vary due to the different types of light-emitting layers. Therefore, electron injection layers are only set for predetermined light-emitting layers. For example, among red (R), green (G), and blue (B) light-emitting layers, only the specific blue (B) layer has an electron injection layer made of LiF. In order to form electron injection layers only for the necessary light-emitting layers, a method called mask evaporation can be used. However, this method requires not only the use of a mask that is deposited at a specific location, but also a high degree of precision in aligning the mask with the substrate. When there are multiple evaporation sites on the substrate, this alignment is very difficult.

[0008] In recent years, a jetting method (liquid jetting method) has been proposed, which involves jetting a composition formed by dissolving a predetermined material in water to create a predetermined pattern. However, when using this jetting method to form the electron injection layer of LiF, the water residue in the composition within the luminescent layer reduces the luminescence lifetime and also presents the problem of LiF's poor solubility in water and other aqueous solvents. Furthermore, when NaF is used instead of LiF, a suitable electron injection layer cannot be obtained because NaF crystallizes on the surface of the luminescent layer. In addition, when benzene-based or phenyl-based solvents are used instead of aqueous solvents, the luminescent layer is dissolved. Therefore, in all cases, there is a lack of suitable materials and solvents for forming the electron injection layer.

[0009] In view of the above problems, the present invention aims to provide a method for manufacturing an electroluminescent device, an electroluminescent device, and an electronic instrument, wherein, when forming the electron injection layer using a liquid-phase method, not only can the dissolution of the light-emitting layer caused by the composition ink be suppressed, but a suitable electron injection layer can also be formed, resulting in good light-emitting characteristics and light-emitting lifetime. Furthermore, the present invention also aims to provide a method for manufacturing an electroluminescent device, an electroluminescent device, and an electronic instrument that simplifies the manufacturing process by forming the electron injection layer using a simple method.

[0010] To achieve the above objectives, the present invention employs the following method. Specifically, the method for manufacturing an electroluminescent device includes a step of forming multiple light-emitting layers that emit various colors of light, a step of forming an electron injection layer containing an organometallic compound and bringing it into contact with at least one of the multiple light-emitting layers, and a step of forming a layer capable of reducing the metal in the organometallic compound and bringing it into contact with the electron injection layer. Therefore, by forming an electron injection layer containing an organometallic compound according to the present invention, the dissolution of the light-emitting layer can be suppressed, while good wettability with the surface of the light-emitting layer can be obtained. Furthermore, crystallization of the electron injection layer formed on the light-emitting layer can be prevented.

[0011] Furthermore, the characteristic feature is that the layer capable of reducing the metal in the organometallic compound is a cathode. For example, Mg, Ca, and Al can be appropriately used as the layer capable of reducing the metal in the organometallic compound. According to this method, after the metal in the organometallic compound is reduced, it diffuses into the interior of the light-emitting layer, and the metal atoms become integrated with the organic semiconductor molecules in the light-emitting layer, resulting in a high electron injection state. This allows the fabrication of an electroluminescent device in which, when current flows through the anode, holes in the anode are injected into the light-emitting layer, and electrons from the cathode are injected into the light-emitting layer via an electron injection layer, resulting in appropriate light emission due to the combination of holes and electrons.

[0012] Furthermore, this invention is characterized in that the electron injection layer can be formed using a liquid material containing any solvent selected from alcohol-based, ketone-based, ether-based, ester-based, and amide-based solvents. More specifically, multiple light-emitting layers are each divided into regions, and the electron injection layer can be formed by injecting liquid material into the divided regions. According to this method, the organometallic compound is uniformly dissolved in the liquid material to form a composition ink of the same concentration, thus facilitating liquid ejection or printing methods.

[0013] Furthermore, it can prevent crystallization of the electron injection layer formed on the light-emitting layer. In addition, compared with electroluminescent devices equipped with electron injection layers formed by vapor deposition, it can achieve the same level of luminescence characteristics and luminescence lifetime. In particular, when liquid is injected into the area using a liquid ejection method, there is no material waste, the required amount of material can be accurately placed at the desired location, and the manufacturing process is simplified, thus enabling the manufacture of electroluminescent devices at low cost. Therefore, according to the present invention, since the dissolution of the light-emitting layer is suppressed, the organometallic compound dissolves appropriately in the liquid material, resulting in excellent wettability of the light-emitting layer, and thus the formation of the electron injection layer can proceed appropriately.

[0014] Furthermore, this invention relates to a method for manufacturing the electroluminescent device described above, characterized in that the organometallic compound contains at least one metallic element selected from Group 1A, Group 2A, and rare earth elements. Preferably, the metallic element is selected from Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. Moreover, the organometallic compound refers to organometallic coordination compounds such as lithium hydroxyquinoline, substances combining metal and organic matter such as lithium phenylene, and substances combining organic matter and metal salts such as lithium benzoate. Furthermore, the coordination compound is a general term for substances having one or more anion, neutral, or cation ligands coordinated with a metal or metalloid atom or ion as the central atom or ion. Therefore, according to this invention, the electron injection efficiency of the light-emitting layer can be improved.

[0015] Furthermore, the present invention is characterized by the process of forming the aforementioned plurality of light-emitting layers, including a process of forming a light-emitting layer emitting red light, a process of forming a light-emitting layer emitting green light, and a process of forming a light-emitting layer emitting red light, wherein the electron injection layer containing the aforementioned organometallic compound is formed to at least contact the light-emitting layer emitting blue light. According to the present invention, since the electron injection layer is formed to contact the blue light-emitting layer with relatively poor luminous efficiency, the luminous efficiency of each color can be brought closer together.

[0016] The electroluminescent device of the present invention is characterized by comprising multiple light-emitting layers that emit various colors of light, an electron injection layer disposed in contact with at least one of the multiple light-emitting layers and containing an organometallic compound, and a layer disposed in contact with the electron injection layer and capable of reducing the metal in the organometallic compound. Therefore, according to the present invention, by forming an electron injection layer containing an organometallic compound, the dissolution of the light-emitting layers can be suppressed, while also achieving appropriate wettability on the surface of the light-emitting layers. Furthermore, crystallization of the electron injection layer formed on the light-emitting layers can be prevented.

[0017] Furthermore, according to the present invention, the aforementioned light-emitting layer is sandwiched between an anode and a cathode, and the layer capable of reducing the metal in the organometallic compound is the cathode. The layer capable of reducing the metal in the organometallic compound can appropriately use a metal selected from Mg, Ca, and Al. Therefore, according to the present invention, the metal in the organometallic compound is reduced and diffuses into the interior of the light-emitting layer, whereby the metal atoms become integrated with the molecules of the light-emitting layer, resulting in a high electron injection capability. When current flows through the anode, the holes of the anode are injected into the light-emitting layer, and electrons from the cathode are injected into the light-emitting layer via the electron injection layer, achieving appropriate luminescence due to the combination of holes and electrons.

[0018] Furthermore, according to the present invention, the aforementioned plurality of light-emitting layers are divided into regions, and the electron injection layer is formed in the region where it is divided. Therefore, even when a liquid material is used to form the electron injection layer, since the liquid material will not leak outside the region, the electron injection layer can be formed at the precise location.

[0019] Furthermore, the present invention is characterized in that the organometallic compound contains at least one metallic element selected from Group 1A, Group 2A, and rare earth elements. More specifically, it preferably contains a metallic element selected from Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, DV, Ho, Er, Tm, Yb, and Lu. Therefore, according to the present invention, the electron injection efficiency for the light-emitting layer can be improved.

[0020] Furthermore, among the aforementioned multiple light-emitting layers, including the light-emitting layer emitting red light, the light-emitting layer emitting green light, and the light-emitting layer emitting red light, the electron injection layer containing the aforementioned organometallic compound is configured to at least contact the light-emitting layer emitting blue light. This structure allows for a better balance of luminous efficiency among various colors.

[0021] Next, the electronic instrument of the present invention is characterized by having an electroluminescent device as a display mechanism. Therefore, examples of the electronic instrument of the present invention include portable telephones, portable information terminals, watches, word processors, personal computers, and other information processing devices. By employing the electroluminescent device of the present invention, the display portion of these electronic instruments can be manufactured as a display portion with good light-emitting characteristics and long lifespan, resulting in inexpensive electronic instruments. When manufacturing these electronic instruments, the electroluminescent device can be installed in the display portion of various electronic instruments such as portable telephones, portable information processing devices, and watches.

[0022] Figure 1 This is a schematic structural view illustrating the electroluminescent device of the present invention.

[0023] Figure 2 This is a circuit diagram representing an active matrix electroluminescent device.

[0024] Figure 3 This is an enlarged view showing the cross-sectional structure of the display area in an electroluminescent device.

[0025] Figure 4 This is an explanatory diagram illustrating the manufacturing method of an electroluminescent device.

[0026] Figure 5 This is a view illustrating an electronic instrument embodiment of the present invention. In the figure,

[0027] 1. Electroluminescent device, 110b light-emitting layer, 150 electron injection layer.

[0028] 1000, 1100, 1200 electronic instruments

[0029] The present invention will now be described with reference to the accompanying drawings. In the drawings, the scale varies for each layer and component in order to achieve dimensions that are easily identifiable. (Embodiment 1)

[0030] Figure 1 This is a schematic diagram illustrating the electroluminescent device of the present invention, and in particular, a schematic diagram illustrating a specific embodiment applicable to an active matrix type electroluminescent device. Furthermore, this electroluminescent device 1 employs an active driving method using thin-film transistors.

[0031] The electroluminescent device 1 is composed of a structure in which a circuit element portion 14, including a thin-film transistor for use as a circuit element, a pixel electrode (anode) 111, a functional layer 110 including a light-emitting layer (organic electroluminescent layer), a cathode 12 and a sealing portion 3 are stacked sequentially on a substrate 2.

[0032] In this example, a glass substrate is used as substrate 2. Besides glass substrates, various known substrates used in electro-optical devices and circuit boards, such as silicon substrates, quartz substrates, ceramic substrates, metal substrates, plastic substrates, and plastic film substrates, can also be used as substrates in this invention. When multiple pixel regions A, which are light-emitting areas, are arranged in a matrix on substrate 2 beforehand and displayed in color, for example, pixel regions A corresponding to various colors among red (R), green (G), and blue (B) are arranged side-by-side in a predetermined order. Each pixel region A is provided with a pixel electrode 111, and signal lines 132, power lines 133, scan lines 131, and other scan lines for pixel electrodes (not shown in the figure) are provided nearby. The planar shape of the pixel region A can be any shape, such as a circle or an ellipse, in addition to the rectangle shown in the figure.

[0033] Furthermore, the sealing portion 3 is used to prevent water and oxygen intrusion and to prevent oxidation of the cathode 12 or the functional layer 110. It includes a sealing resin coated on the substrate 2 and a sealing substrate 3b (sealing container) bonded to the substrate 2. The sealing resin material can be, for example, a thermosetting resin or a UV-curable resin, and epoxy resin, which is itself a thermosetting resin, is particularly preferred. The sealing resin is pre-coated in a ring around the substrate 2, for example, using a micro-distributor. The sealing substrate 3b is made of glass or metal, and the substrate 2 and the sealing substrate 3b are bonded together with the sealing resin.

[0034] Figure 2 This shows the circuit structure of the electroluminescent device 1 described above. Figure 2 In this design, multiple scan lines 131, multiple signal lines 132 extending along the direction intersecting the scan lines 131, and multiple power lines 133 extending parallel to the signal lines 132 are arranged on the substrate 2. Furthermore, the aforementioned pixel region A is formed at each focal point where the scan lines 131 and signal lines 132 intersect. The signal lines 132 are connected, for example, to a data-side drive circuit 103 that includes a shift register, an electrical shifter, a video line, and an analog switch. The scan lines 131 are connected to a scan-side drive circuit 104 that includes a shift register and an electrical shifter.

[0035] Pixel region A includes a first thin-film transistor 123 for switching, which supplies a scan signal to the gate electrode via a scan line 131; a holding capacitor 135 for holding the image signal supplied by the thin-film transistor 123 via a signal line 132; a second thin-film transistor 124 for driving the image signal held by the holding capacitor 135 to the gate electrode; a pixel electrode 111 (anode) through which a drive current from the power line 133 flows when the thin-film transistor 124 is electrically connected to the power line 133; and a functional layer 110 sandwiched between the pixel electrode 111 and the counter electrode 12 (cathode). The functional layer 110 includes an organic electroluminescent layer that serves as a light-emitting layer.

[0036] Once scan line 131 in pixel region A is driven, turning on the first thin-film transistor 123, the potential of signal line 132 is held by holding capacitor 135, and the conduction state of the second thin-film transistor 124 depends on the state of this holding capacitor 135. Furthermore, current flows through the channel of the second thin-film transistor 124 from power line 133 to pixel electrode 111, and then through functional layer 110 to the counter electrode 12 (cathode). The functional layer then emits light according to the amount of current.

[0037] Figure 3 This is an enlarged view of the cross-sectional structure of the display area in the aforementioned electroluminescent device 1. Figure 3The diagram shows the cross-sectional structure of three pixel regions corresponding to each of the colors red (R), green (G), and blue (B). As described above, the electroluminescent device 1 is composed of a circuit element portion 14, such as a TFT circuit, a pixel electrode (anode) 111, a light-emitting element portion 11 with a functional layer 110, and a cathode 12, which are sequentially stacked on a substrate 2. In this electroluminescent device 1, light emitted from the functional layer 110 toward the substrate 2 passes through the circuit element portion 14 and the substrate 2 and is emitted toward the lower side (observer side) of the substrate 2. At the same time, light emitted from the functional layer 110 toward the opposite side of the substrate 2 is reflected by the cathode 12, passes through the circuit element portion 14 and the substrate 2, and is emitted toward the lower side (observer side) of the substrate 2.

[0038] A substrate protective film 2c, composed of a silicon oxide film on the substrate 2, is formed on the circuit element portion 14. An island-shaped semiconductor film 141, composed of polycrystalline silicon, is formed on this substrate protective film 2c. A source region 141a and a drain region 141b are formed on the semiconductor film 141 by high-concentration P ion implantation. The portion without P implantation becomes the channel region 141c. A transparent gate insulating film 142, covering the substrate protective film 2c and the semiconductor film 141, is then formed on the circuit element portion 14. A gate electrode 143 (scan line) composed of Al, Mo, Ta, Ti, W, etc., is formed on the gate insulating film 142. A transparent first interlayer insulating film 144a and a second interlayer insulating film 144b are formed on the gate electrode 143 and the gate insulating film 142. The gate electrode 143 is positioned corresponding to the channel region 141c of the semiconductor film 141. Furthermore, contact holes 145 and 146 are formed, penetrating the first and second interlayer insulating films 144a and 144b, and respectively connecting to the source region 141a and drain region 141b of the semiconductor film 141. On the second interlayer insulating film 144b, a transparent pixel electrode 111 made of ITO or the like is patterned according to a predetermined shape, and one contact hole 145 is connected to this pixel electrode 111. The other contact hole 146 is connected to the power line 133. In this way, a driving thin-film transistor 123 connected to each pixel electrode 111 can be formed on the circuit element portion 14. The aforementioned holding capacitor 135 and the switching thin-film transistor 124 are also formed on the circuit element portion 14. Figure 3 These illustrations have been omitted.

[0039] The light-emitting element portion 11 mainly consists of a functional layer 110 stacked on each of the plurality of pixel electrodes, and a retaining portion 112 separating the functional layers 110. A cathode 12 is disposed on the functional layer 110. The light-emitting layer, as the light-emitting element, is composed of the pixel electrode 111, the cathode 12, and the functional layer 110. The pixel electrode 111 is formed of ITO, forming a generally rectangular pattern when viewed from above. The thickness of this pixel electrode 111 is preferably 50 to 200 nanometers, and particularly preferably around 150 nanometers.

[0040] As shown in the figure, the embankment portion 112 is formed by stacking an inorganic embankment layer 112a (first embankment layer) on the substrate 2 side and an organic embankment layer 112b (second embankment layer) on the substrate 2. The inorganic embankment layer 112a is composed of inorganic materials such as SiO2 and TiO2. The organic embankment layer 112b is formed of a photoresist with heat resistance and solvent resistance, such as acrylic resin and polyimide resin.

[0041] The functional layer 110 comprises a hole injection / transport layer 110a formed on the pixel electrode 111 and a light-emitting layer 110b formed adjacent to the hole injection / transport layer 110a. The hole injection / transport layer 110a has the function of injecting holes into the light-emitting layer 110b, and also has the function of transporting holes within the hole injection / transport layer 110a. By providing the hole injection / transport layer 110a between the pixel electrode 111 and the light-emitting layer 110b, the luminous efficiency, lifetime, and other characteristics of the light-emitting layer 110b can be improved. Moreover, in the light-emitting layer 110b, the holes injected by the hole injection / transport layer 110a combine with electrons injected from the cathode in the light-emitting layer to emit light.

[0042] The light-emitting layer 110b is composed of three light-emitting layers with different emission wavelengths: a red light-emitting layer 110b1 that emits red (R), a green light-emitting layer 110b2 that emits green (G), and a blue light-emitting layer 110b3 that emits blue (B). The light-emitting layers 110b1 to 110b3 are arranged in a predetermined order (e.g., in a strip).

[0043] The electron injection layer 150 is a layer containing an organometallic compound, which promotes the injection of electrons from the cathode 12 into the light-emitting layer 110b. Furthermore, in this embodiment, the electron injection layer 150 is formed only between the blue light-emitting layer 110b3 (the light-emitting layer emitting blue light) and the cathode 12, among the red (R), green (G), and blue (B) light-emitting layers 110b. The electron injection layer 150 is formed of a lithium hydroxyquinoline coordination compound with lithium as the central metal, and its thickness is preferably in the range of 2 to 5 nanometers, and particularly preferably around 2 nanometers. The material used for the electron injection layer 150 can be any substance other than lithium hydroxyquinoline coordination compounds. Preferably, it contains a metal element selected from Group 1A, Group 2A, and rare earth elements, such as coordination compounds containing a metal element selected from Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. Examples of coordination compounds include sodium hydroxyquinoline coordination compounds. Furthermore, the electron injection layer 150 can be formed by dissolving the aforementioned lithium hydroxyquinoline coordination compound in a liquid material (described later) into an ink composition, which can be formed by spraying it onto the light-emitting layer 110b3 using a liquid jetting method (inkjet printing).

[0044] The cathode (counter electrode) 12 is formed on the entire surface of the light-emitting element portion 11 beforehand, and pairs with the pixel electrode 111 to allow current to flow through the functional layer 110. This cathode 12, as a material capable of reducing lithium (Li) ions, is in this example formed by stacking a calcium layer 12a and an aluminum layer 12b. It is preferable to place a material capable of reducing the metal in the organometallic compound forming the electron injection layer on the cathode near the light-emitting layer side. The thickness of the calcium layer 12a is preferably in the range of 2 to 50 nanometers. Furthermore, since the aluminum layer 12b reflects the light emitted from the light-emitting layer 110b to the substrate 2 side, it is preferably composed of an Ag film, a laminate of Al and Ag, etc., in addition to an aluminum film. Its thickness is preferably in the range of 100 to 1000 nanometers. In this embodiment, although calcium (Ca) is used as the material capable of reducing lithium ions, it is not limited to calcium; Mg or Al can also be used.

[0045] In other words, in the blue (B) pixel region, a pixel electrode (anode) 111, a hole injection / transport layer 110a, a light-emitting layer 110b3, an electron injection layer 150, and a cathode 12 are stacked sequentially from the substrate 2 side. Furthermore, in the red (R) and green (G) pixel regions, a pixel electrode (anode) 111, a hole injection / transport layer 110a, a light-emitting layer 110b1 (or light-emitting layer 110b2), and a cathode 12 are stacked sequentially from the substrate 2 side.

[0046] In the electroluminescent device 1 configured in this way, within the blue light-emitting layer 110b3 on the cathode 12 side, where the electron injection layer 150 is disposed, effective light emission is achieved due to the promotion of electron injection from the cathode 12. On the other hand, in the red light-emitting layer 110b1 (the light-emitting layer emitting red-based colored light) and the green light-emitting layer 110b2 (the light-emitting layer emitting green-based colored light), the calcium layer 12a of the cathode 12 is in direct contact with the light-emitting layer 110b, thus injecting electrons into the light-emitting layer 110b. Moreover, the electroluminescent device 1 in this embodiment can obtain the same level of light emission characteristics and light emission lifetime as electroluminescent devices with electron injection layers formed by vapor deposition.

[0047] The following is for reference only. Figure 4 (a) to (d) describe the manufacturing method of the electroluminescent device 1 described above. The substrate 2 has already formed the structures as described above. Figure 3 The assembly shown includes a circuit element portion 14 containing a thin-film transistor, a dam portion 112 (organic dam layer 112a, inorganic dam layer 112b), and a pixel electrode 111.

[0048] The manufacturing method described in this example includes (1) a cavity injection / delivery layer formation process, (2) a blue light-emitting layer formation process, (3) an electron injection layer formation process, (4) a red and green light-emitting layer formation process, (5) a cathode formation process, and (6) a sealing process. The manufacturing method described here is only one example, and other processes can be added if necessary. In addition, a liquid ejection method is used in the electron injection layer formation process.

[0049] (1) Cavity injection / delivery layer formation process

[0050] like Figure 4 As shown in (a), a hole injection / delivery layer 110a is formed on the substrate 2 on which the pixel electrode 111 is formed. In the hole injection / delivery layer formation process, a composition containing a hole injection / delivery layer forming material is sprayed onto the pixel electrode 111, for example, using a liquid ejection method. Then, a drying and heat treatment are performed to form the hole injection / delivery layer 110a on the pixel electrode 111. Subsequent processes, including this hole injection / delivery layer formation process, are preferably performed in an atmosphere free of moisture and oxygen. For example, an inert gas atmosphere such as a nitrogen atmosphere or an argon atmosphere is preferred.

[0051] The sequence for forming the cavity injection / delivery layer using the liquid ejection method is as follows: An ink composition containing the cavity injection / delivery layer material is filled into a nozzle (not shown) for ejecting liquid. The nozzle of the nozzle is positioned opposite the pixel electrode 111 located within the opening of the embankment portion 112. While the nozzle and substrate 2 are moved relative to each other, ink droplets with controlled droplet volume are ejected from the nozzle 1. The ejected ink droplets are then dried to evaporate the polar solvent contained in the ink composition, thus forming the cavity injection / delivery layer.

[0052] As the composition used herein, for example, a composition formed by dissolving a mixture of polythiophene derivatives such as polyethylene dioxothiophene (PEDOT) and polystyrene sulfonic acid (PSS) in a polar solvent can be used. Examples of polar solvents include isopropanol (IPA), n-butanol, γ-butyrolactone, N-methylpyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinedione (DMI) and its derivatives, carbitol acetate, butyl carbitol acetate, and other glycol ethers. More specifically, a composition can be composed of 12.5% ​​by weight of a PEDOT:PSS mixture (PEDOT / PSS = 1:20), 1.44% by weight of PSS, 10% by weight of IPA, 27.48% by weight of NMP, and 50% by weight of DMI. Furthermore, the viscosity of the composition is preferably around 2 to 20 ps, ​​and particularly preferably around 4 to 15 ps.

[0053] (2) Blue light-emitting layer formation process

[0054] like Figure 4 As shown in (b), a blue light-emitting layer 110b3 is formed on the blue pixel electrode 111 on which the hole injection / delivery layer 110a is stacked. That is, for example, an ink composition containing a light-emitting layer material is sprayed onto the hole injection / delivery layer 110a using a liquid ejection method, followed by drying and heat treatment, to form the blue light-emitting layer 110b3 in the opening portion formed in the embankment portion 112.

[0055] In the light-emitting layer formation process, to prevent the redissolution of the hole injection / transport layer 110a, a nonpolar solvent that is insoluble in the hole injection / transport layer 110a is used as the solvent for the ink composition used in forming the light-emitting layer. In this case, to improve the wettability of the insoluble nonpolar solvent on the surface of the hole injection / transport layer 110a, a surface modification process is preferably performed before the formation of the light-emitting layer. The surface modification process is performed by coating the hole injection / transport layer 110a with a liquid spraying method, spin coating method, or dip coating method using the same solvent as or similar to the aforementioned nonpolar solvent, followed by drying. Moreover, the surface modification solvent used here can be the same solvent as the nonpolar solvent in the ink composition, for example, cyclohexylbenzene, dihydrobenzofuran, trimethylbenzene, tetramethylbenzene, etc., and a solvent similar to the nonpolar solvent used in the ink composition, for example, toluene, xylene, etc.

[0056] Furthermore, the sequence for forming the luminescent layer using the liquid ejection method is as follows: For example, an ink composition containing a blue luminescent layer material is filled into a printhead (not shown). The nozzle of the printhead faces the blue cavity injection / delivery layer 110a located within the opening of the embankment portion 112. While the printhead and substrate 2 are moved relative to each other, ink droplets with controlled droplet volume are ejected from the nozzle. The ejected ink droplets expand on the cavity injection / delivery layer 110a, filling the opening of the embankment portion 112. Next, the ejected ink droplets are dried to evaporate the non-polar solvent contained in the ink composition, forming the blue luminescent layer 110b3.

[0057] Examples of luminescent materials constituting the light-emitting layer include fluorane polymer derivatives, (poly)-p-phenylenevinylene derivatives, polyphenylene derivatives, polyfluorane derivatives, polyvinylcarbazole, polythiophene derivatives, dinaphthalene-based pigments, coumarin-based pigments, rhodamine-based pigments, soluble low-molecular-weight organic electroluminescent materials among other benzene derivatives, and high-molecular-weight organic electroluminescent materials. Examples of materials that can also be used include rubrene, dinaphthalene-based pigments, 9,10-diphenylanthracene, tetraphenylbutadiene, nilored, coumarin 6, and quinacrine. On the other hand, nonpolar solvents that are insoluble in the hole injection / transport layer 110a are preferred; for example, cyclohexylbenzene, dihydrobenzofuran, trimethylbenzene, and tetramethylbenzene can be used.

[0058] (3) Electron injection layer formation process

[0059] Next, as Figure 4As shown in (b), an electron injection layer 150 is formed on the blue emitting layer 110b3. As described above, this electron injection layer, used to facilitate the injection of electrons from the cathode into the emitting layer, can be formed using a hydroxyquinoline lithium coordination compound. That is, an ink composition in which the hydroxyquinoline lithium coordination compound is dissolved in a solvent is sprayed onto the blue emitting layer 110b3 using a liquid spraying method, followed by drying and heat treatment to form the electron injection layer 150.

[0060] The solvent (liquid material) in the ink composition used in this electron injection layer formation process has the characteristic of being insoluble in the blue luminescent layer 110b3, exhibiting excellent wettability on the surface of the blue luminescent layer 110b3, and can be a solvent suitable for dissolving hydroxyquinoline lithium coordination compounds. Specifically, alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, amide-based solvents, etc., can be used, and isopropanol can be used as an alcohol-based solvent.

[0061] As part of the sequence for forming the electron injection layer using a liquid ejection method, for example, an ink composition containing a lithium hydroxyquinoline coordination compound is filled into a printhead (not shown). The nozzle of the printhead is positioned opposite the blue luminescent layer 110b3 located within the opening of the embankment portion 112. While the printhead and the substrate 2 are moved relative to each other, ink droplets with controlled droplet volume are ejected from the nozzle. By allowing the ejected ink droplets to expand on the blue luminescent layer 110b3, they can be positioned within the opening of the embankment portion 112. The ejected ink droplets are then dried to evaporate the solvent contained in the ink composition, forming the electron injection layer 150.

[0062] In this manufacturing method, since the lithium hydroxyquinoline coordination compound is dissolved in isopropanol and sprayed out as an ink composition, the dissolution of the blue emitting layer 110b3 can be suppressed, and appropriate wettability of the surface of the blue emitting layer 110b3 can be obtained. Furthermore, since the lithium hydroxyquinoline coordination compound is also dissolved in isopropanol to form an ink composition of uniform concentration, the liquid spraying method is easy to implement. In addition, crystallization of the electron injection layer formed on the surface of the blue emitting layer 110b3 can be prevented. Moreover, the electroluminescent device 1 equipped with an electron injection layer formed by the liquid spraying method of this embodiment can obtain the same level of luminescence characteristics and luminescence lifetime as an electroluminescent device equipped with an electron injection layer formed by vapor deposition. Furthermore, the liquid spraying method allows for the easy formation of the electron injection layer 150 between the blue emitting layer 110b3 and the cathode, among the red (R), green (G), and blue (B) emitting layers 110b. In addition, the liquid spraying method results in less material waste and allows for precise placement of the required amount of material at the desired location.

[0063] This liquid ejection method can be categorized into several types, including electrically controlled, pressurized vibration, electromechanical conversion, electrothermal conversion, and electrostatic attraction. Electrically controlled ejection uses charged electrodes to electrify the material, and deflection electrodes control the material's flight direction from the nozzle. Pressurized vibration involves applying ultra-high pressure to the material, causing it to eject from one side of the nozzle. Without control voltage, the material travels in a straight line and exits the nozzle; however, applying control voltage creates electrostatic repulsion between the materials, scattering them and preventing them from exiting the nozzle. Electromechanical conversion (piezoelectric) utilizes the property of piezoelectric elements deforming upon receiving pulsed electrical signals. The deformation of the piezoelectric element applies pressure through a flexible material into the space containing the material, forcing it out. Electrothermal conversion uses a heater within the material storage space to rapidly vaporize the material, generating bubbles, and the pressure of these bubbles propels the material out of the space. Regarding electrostatic attraction, a slight pressure is applied within the space where the material is stored, forming a meniscus of material in the nozzle. Electrostatic attraction is then applied under these conditions to draw the material out. Other methods can also be used, such as changing the fluid viscosity using an electric field or using a discharge spark. Among the aforementioned ejection technologies, piezoelectric methods, because they do not heat the material, have the advantage of having minimal impact on the material's composition.

[0064] (4) Red and green light-emitting layer formation process

[0065] Then, as Figure 4 As shown in (c), a red light-emitting layer 110b1 and a green light-emitting layer 110b2 are formed on the red (R) and green (G) pixel electrodes 111, which are stacked with a hole injection / delivery layer 110a. This red and green organic light-emitting layer formation process is performed in the same sequence as the blue light-emitting layer formation process described above. That is, an ink composition containing a light-emitting layer material is sprayed onto the hole injection / delivery layer 110a using a liquid ejection method, followed by drying and heat treatment, to form a light-emitting layer within the opening formed in the embankment portion 112.

[0066] (5) Cathode formation process

[0067] Furthermore, such as Figure 4As shown in (d), a counter electrode (cathode) 12 is formed in pair with the pixel electrode (anode) 111. That is, a calcium layer 12a and an aluminum layer 12b are sequentially stacked over the entire area of ​​the shore portion 112 where the electron injection layer 150 is stacked and the substrate 2 containing the light-emitting layer 110b to form the cathode 12. Using this method, the cathode 12 is stacked over the entire area of ​​the light-emitting layer 110b, including the areas where the red light-emitting layer 110b1 and the green light-emitting layer 110b2 are formed, and the area where the blue light-emitting layer 110b3, where the electron injection layer 150 is stacked, forming light-emitting layers corresponding to red (R), green (G), and blue (B) colors, respectively. The cathode 12 is preferably formed by methods such as vapor deposition, sputtering, or CVD; vapor deposition is particularly preferred from the viewpoint of preventing damage to the light-emitting layer 110b. Furthermore, a protective film such as SiO2 or SiN for preventing oxidation can also be provided on the cathode 12.

[0068] (6) Sealing process

[0069] Finally, a sealing resin is used to seal the substrate 2, which has formed the light-emitting layer (light-emitting element), and the sealing substrate 36 (see Appendix). Figure 1 The sealing process involves, for example, coating the periphery of the substrate 2 with a sealing resin composed of thermosetting resin or UV-curable resin, and then placing the sealing substrate 3b on the sealing resin. The sealing process is preferably performed in an inert gas atmosphere such as nitrogen, argon, or helium. If performed in the atmosphere, moisture and oxygen can easily penetrate the cathode 12 through defects such as pinholes, causing oxidation, which is undesirable.

[0070] Next, the wiring of the cathode 12 to the substrate 2 is connected, and the wiring of the circuit element section 14 (see...) is also connected. Figure 1 It is connected to the driver IC, thus creating the electroluminescent device 1 in this example.

[0071] Using the manufacturing method described above, an electron injection layer 150 can be formed only in the blue light-emitting layer 110b3 among the three light-emitting layers: red (R), green (G), and blue (B). This allows the formation of the blue light-emitting layer 110b3 to be separated from the formation of the red light-emitting layer 110b1 and the green light-emitting layer 110b2, and performed before or after the electron injection layer formation process.

[0072] Furthermore, in the above manufacturing method, the liquid ejection method is used in all of the following steps: (1) cavity injection / delivery layer formation process, (2) blue light-emitting layer formation process, (3) electron injection layer formation process, and (4) red and green light-emitting layer formation process, thus simplifying the process.

[0073] In this embodiment, although the method of forming the red light-emitting layer 110b1 and the green light-emitting layer 110b2 after forming the electron injection layer 150 on the blue light-emitting layer 110b3 is described, it is also possible to selectively form the electron injection layer 150 on the blue light-emitting layer 110b3 after forming the blue light-emitting layer 110b3, the red light-emitting layer 110b1, and the green light-emitting layer 110b2. In this case, except for the different formation order of the red light-emitting layer 110b1 and the green light-emitting layer 110b2 and the electron injection layer 150, the same process as in this embodiment can be used. By performing the electron injection layer 150 formation process after forming the blue light-emitting layer 110b3, the red light-emitting layer 110b1, and the green light-emitting layer 110b2, the harmful effects of drying and heat treatment of each light-emitting layer on the electron injection layer can be prevented.

[0074] (Implementation Method 2)

[0075] The following uses the appendix Figure 1 and 3 This describes Embodiment 2 of the electroluminescent device. In Embodiment 1, unlike the case where the light emitted from the functional layer 110 is emitted from the lower side (observer side) of the substrate 2, in this embodiment it is emitted from the upper side of the sealing substrate 3b. The main difference between this embodiment and Embodiment 1 lies in the material composition; only the differences from Embodiment 1 will be described in this embodiment.

[0076] Since this embodiment extracts light from the sealed substrate 3b located on the opposite side of the substrate 2, the substrate 2 can be either a transparent substrate or an opaque substrate. For opaque substrates, examples include those made of ceramics such as alumina, metal sheets such as stainless steel with surface oxidation treatment, as well as thermosetting resins and thermoplastic resins. Furthermore, the pixel electrode 111 is not necessarily limited to a transparent material; a suitable material that meets the anode function requirements can be used, and a light-reflective material is preferred, such as aluminum. When a transparent metal such as ITO is used as the pixel electrode 111, it is preferable to form an aluminum thin film or similar structure beneath it, creating a light-reflective structure. The cathode 12 material must also be transparent; a transparent metal such as ITO can be used. An aluminum thin film with a transparent thickness can also be formed between the ITO and the electron injection layer 150. The transparent film thickness is preferably 50 nanometers or less. By forming this aluminum thin film, not only can the electron injection performance of the electron injection layer 150 be improved, but plasma damage can also be suppressed when ITO is formed by sputtering. In addition, the light-emitting layer 110b can be protected from the penetration of moisture and oxygen into the cathode 12. Moreover, the electron injection layer 150 can be made of the same material as in Embodiment 1. The material used for the sealing substrate 3b can be a suitable material with transparency.

[0077] In an electroluminescent device with this structure, while achieving the same effect as in Embodiment 1, light emitted from the functional layer 110 can also be emitted from the sealing substrate 3b side. (Embodiment 3)

[0078] Figure 5 (a) to (c) illustrate examples of embodiments of the electronic instrument of the present invention. In these examples, the electronic instrument is equipped with the electroluminescent device of the present invention, such as the electroluminescent device described above, as a display mechanism. Figure 5 (a) is a perspective view showing an example of a portable telephone. Figure 5 In (a), the symbol 1000 represents the display portion using the above-described display device. Figure 5 (b) is a perspective view showing an example of a watch-type electronic instrument. Figure 5 In (b), symbol 1100 represents the main body of the watch, and symbol 1101 represents the display part using the above-mentioned display device. Figure 5 (c) is an axonometric view showing an example of a portable information processing device such as a word processor or personal computer. Figure 5 In (c), symbol 1200 represents an information processing device, symbol 1202 represents an input part such as a keyboard, symbol 1204 represents the main body of the information processing device, and symbol 1206 represents the display part using the above-mentioned display device. Figure 5 The various electronic instruments represented by (a) to (c) are equipped with the electroluminescent device of the present invention in their display parts, thus achieving good light-emitting characteristics and light-emitting lifespan, while also reducing the price of some electronic instruments.

[0079] The above description, with reference to the accompanying drawings, outlines suitable embodiments of the present invention. However, it should be understood that the invention is not limited to the embodiments described. The various shapes and combinations of the constituent materials shown in the above examples are merely illustrative, and various modifications can be made according to design requirements without departing from the spirit of the invention.

Claims

1. A device for an LED-free electro-cooled light atmosphere coating for automotive interior and exterior trim, characterized in that, The system includes an electroluminescent coating material, a power supply system, and a control module. The electroluminescent coating material is applied to the interior and exterior surfaces of an automobile. The power supply system is connected to the electroluminescent coating material to provide it with electrical energy. The control module controls the output of the power supply system to adjust the luminous effect of the electroluminescent coating.

2. The automotive interior and exterior trim LED-free electro-cooled light atmosphere coating device according to claim 1, characterized in that, The electroluminescent coating material is composed of electroluminescent material, binder and solvent.

3. The automotive interior and exterior trim LED-free electro-cooled light atmosphere coating device according to claim 2, characterized in that, The electroluminescent material is an inorganic or organic electroluminescent material.

4. The automotive interior and exterior trim LED-free electro-cooled light atmosphere coating device according to claim 1, characterized in that, The power supply system includes a power supply and a power management module, which is used to stabilize and regulate the power output.

5. The automotive interior and exterior trim LED-free electro-cooled light atmosphere coating device according to claim 1, characterized in that, The control module includes a microcontroller and an input device and a communication interface connected to the microcontroller. The input device is used to receive control commands input by the user, and the communication interface is used to communicate with external devices.

6. The automotive interior and exterior trim LED-free electro-cooled light atmosphere coating device according to claim 1, characterized in that, The light-emitting effect includes the color, brightness, and flashing mode.

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